An experiment was conducted to investigate the sound pressure patterns on the melon of odontocetes by using four broadband hydrophones embedded in suction cups to measure echolocation signals on the surface of the forehead of two harbor porpoises (Phocoena phocoena). It has long been hypothesized that the special lipids found...
Physical, optical, and acoustical data from Monterey Bay, California, USA, describing the distributions of phytoplankton, zooplankton, and small fish as well as gradients in the physical habitat were used to examine the interactions between vertically compressed plankton structures (thin layers), their consumers, and the local physical forces they experience. The...
Groups of spinner dolphins have been shown to cooperatively herd small prey. It was hypothesized that the strong group coordination is maintained by acoustic communication, specifically by frequency-modulated whistles. Observations of groups of spinner dolphins foraging at night within a sound-scattering layer were made with a multibeam echosounder while the...
Broadband simulated dolphin echolocation signals were used to measure the ex situ backscatter properties of mesopelagic boundary community MBC in order to gain a better understanding of the echolocation process of spinner dolphins foraging on the MBC. Subjects were captured by trawling with a 2-m-opening Isaacs-Kidd Midwater Trawl. Backscatter measurements...
This study presents the first target strength measurements of Dosidicus gigas, a large squid that is a key predator, a significant prey, and the target of an important fishery. Target strength of live, tethered squid was related to mantle length with values standardized to the length squared of −62.0, −67.4,...
The hypothesis that sounds produced by odontocetes can debilitate fish was examined. The effects of simulated odontocete pulsed signals on three species of fish commonly preyed on by odontocetes were examined, exposing three individuals of each species as well as groups of four fish to a high-frequency click of a...
The characteristics of acoustic echoes from six species of deep-dwelling (up to 400 m) Hawaiian Lujanid snappers were determined by backscatter measurements at the surface. A broadband linear frequency-modulated signal and a short dolphinlike sonar signal were used as the incident signals. The fish were anesthetized and attached to a...
A broadband sonar system and digital camera with strobe lights were mounted on a vertically profiling frame with a depth sensor. The echo strengths and densities of animals within individual mesopelagic boundary community patches were investigated as a function of depth. Time and distance from shore were also investigated. Simultaneous...
Acoustic backscattering strength is often used as an index of biomass; however, the relationship between these variables has not been directly validated. Relationships were investigated between acoustic cross section at 200 kHz, measured as part of a previous study, and measured values of length, biovolume, dry weight, ash-free dry weight,...
A 200-kHz echosounder modified to digitize the envelope of the received echoes directly into a computer was used to measure the ex situ target strength (TS) of live animals from the Hawaiian mesopelagic boundary community as a function of animal size, tilt and roll angle, and biological classification. Dorsal aspect...
Variation in cold-hardiness traits, and their extent of genetic control and interrelationships, were investigated
among individuals (clones) within a single large full-sib family of coastal Douglas-fir (Pseudotsuga menziesii var.
menziesii (Mirb.) Franco) from Oregon. Cold injury to needle, stem, and bud tissues was evaluated in fall 1996 and
spring 1997...
Abstract: Genetic variation in drought hardiness traits and their genetic correlations with growth potential and17re1c6overy
traits were investigated in 39 full-sib families of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.)
Franco) from southwestern British Columbia. Seedlings of these families were grown in raised nursery beds and subjected
to three moisture...
Abstract: Relationships between tree traits and tree value for lumber production were investigated. For the purposes of
estimating relative economic weights for use in multitrait selection in coastal Douglas-fir (Pseudotsuga menziesii
(Mirb.) Franco var. menziesii), tree height, diameter at breast height, and branch diameter were measured on 164 trees
(ages...
Pollen contamination was investigated in one block (block 4) of a 10-block Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seed orchard complex in western Oregon. Blocks (25 clones each) represent different breeding zones; thus, contaminant pollen sources not only included the adjacent natural stand of Douglas-fir, but also other blocks within the...
We compared estimates of bacterial abundance and of average bacterial cell size based on direct counts of bacterioplankton cells stained with acridine orange (AO) or 4’-6-diamidino-2-phenylidole (DAPI). Estimates of numbers mll–1 of bacteria stained with DAPI were on average 70% (range 57–82%) of bacterial counts made with AO as the...
Small, aloricate ciliates with equivalent spherical cell diameters <20 µm (biovolume <4,000 µm3) compose, on average, 4–57% of the total biomass of heterotrophic (apochlorotic) nanoplankton in diverse marine systems. Biomass production of nanoplanktonic ciliates in a southeastern U.S. estuary was also a significant part of the total production of heterotrophic...
Horizontal transects of fluorescence measurements have been used extensively to investigate phytoplankton patchiness. Variance spectra have been calculated from these data, thus quantifying spatial heterogeneity as a function of length scale. Analysis of such fieldwork and associated theoretical investigations is based on the assumption that horizontal patchiness is isotropic. Three...
Iron is recognized as a key element regulating primary production in large regions of the ocean, but nothing is known of its direct effect on higher trophic levels. Two species of heterotrophic protozoa were thus fed iron-rich and iron-poor bacterial prey and their growth and metabolism examined. Maximum growth rates...
There is considerable interest in the biogeochemical cycling of cadmium (Cd) and phosphate (PO4) in surface waters, driven in part by the ongoing development of a paleonutrient proxy that utilizes Cd preserved in fossil planktonic foraminifera to determine past PO4 utilization efficiencies in ocean surface waters. The present article reports...
A comprehensive, joint Soviet-American study of the chemistry of Lake Baikal, the world’s deepest (1,632 m) lake, was carried out in July 1988. In this paper, we report the major, minor, and preliminary trace element concentrations for three profiles obtained at or near the deepest and central part of the...
A Russian–American fieldwork effort on Lake Baikal, its tributaries, and surrounding hot springs was undertaken in June–July 1991. Here we report on aspects of major ion (Ca2+, Mg2+, Na+, K+, Alk, Cl–, SO42–) and several minor and trace element (Li isotopes, Sr isotopes, Ba, Al, V, Cr, Ni, Cu, Ge,...
Stratified bongo net samples taken at depths between 0 and 500 m at Ocean Station “P” in the subarctic Pacific in early July 1971 have been analyzed to determine the vertical structure of the zooplankton community. Distributions for 99 categories of animals have been grouped by factor analysis into five...
Several species of the copepod genus Acartia are shown from existing data to complete each molt-to-molt phase of the life cycle in a constant time period. This molting pattern is termed isochronal development. Increase in mass at each stage is a nearly constant fraction of the weight at the beginning...
Rates of molting of a specific copepodite stage can be determined by sorting the stage from a new collection, waiting, then counting the number that have molted to the next stage in the interval. In principle, stage duration can be determined as the inverse of the measured rate, and molting...
It has been suggested that production in offshore waters of the subarctic Pacific is limited by availability of dissolved Fe. Although that is not yet adequately established, the functional consequences of the limitation (if it exists) can be characterized from the results of the Subarctic Pacific Ecosystem Research (SUPER) program....
Storage lipids of fifth copepodites (C5) of Culanus finmarchicus from Georges Bank and the Gulf of Maine were quantified from video images and by Iatroscan (thin-layer chromatography with flame-ionization detection, FID). Oil withdrawn from the oil sac by micropipette was pure wax ester (WE); triacylglycerols (TAG) were elsewhere in the...
The spatial distribution of plankton is highly aggregated, so one might expect that a vertically migrating animal enters a biotic environment that is markedly different each evening and that the changes in environment between daylight periods spent at depth are equally great. To measure the extent of these changes, as...
An attempt has been made to interbreed populations of Acartia clausi from Woods Hole, Massachusetts, and Yaquina Bay, Oregon. Individuals from these populations are morphologically similar, but differ somewhat in size. Cultures from both sources produced many successive generations in the laboratory, but interbreeding with production of viable offspring did...
The euphotic zone below the deep chlorophyll maximum layer (DCML) at Station ALOHA (a long-term oligotrophic habitat assessment; 22º45′N, 158º00′W) transects the nearly permanently stratified upper thermocline. Hence, seasonal changes in solar radiation control the balance between photosynthesis and respiration in this lightlimited region. Combining profiles of radiance reflectance, algal...
Algal chlorophyll and carotenoid distributions were measured periodically in the euphotic zone of Sta. ALOHA (22º45′N, 158º00′W) between February 1989 and October 1991 to document the variability in phytoplankton abundance and composition. The annual mean depth-integrated (O-200 db) concentration of Chl a displayed significant interannual variability. Seasonal patterns in Chl...
Few studies have examined the partitioning of organic matter in upwelling systems, despite the fact that these systems play a key role in carbon and nitrogen budgets in the ocean. We examined the production and partitioning of phytoplankton-derived organic matter in deck incubations off Oregon during the upwelling season. During...
Axenic cultures of 25 species of unicellular marine algae were tested for their ability to utilize nine common amino acids, supplied at high concentrations in batch culture, as a nitrogen source; most species were able to use several amino acids, although growth was often slower than on nitrate nitrogen. The...
Uptake of nitrogenous nutrients by microplankton off the Washington and Oregon coasts was measured during the 1985 upwelling period. Nitrogen uptake rates in low-NO3- waters (<5 μM) were 0.020–0.258 μmol N liter-1 h-1 and were primarily supported by regenerated nitrogen (71% of total uptake). Nitrogen uptake rates in high-NO3- waters...
Using 15N-labeled NH4+, we assessed the time-course of NH4+ uptake, the parameters of saturation kinetics, and the rates of incorporation of NH4+ into trichloroacetic acid-insoluble material by Chesapeake Bay phytoplankton. The amount of NH4+ taken up by the phytoplankton increased linearly with time for 2 h for all samples growing...
Diel periodicity in NH4+ uptake and regeneration in the nutrient-rich environment of the oceanic subarctic Pacific was examined. Surface water was incubated in large shipboard microcosms that allowed repeated sampling of the planktonic community for NH4+ cycling rates, bacterial production rates, and population densities of the dominant autotrophs and heterotrophs....
The relative contribution of various inorganic and organic forms of nitrogen to the nitrogen requirements of picoplankton was examined with 15N tracers. Size fractionation was used to measure uptake by <1-μM size microorganisms, and inhibitors of protein synthesis were used to separate procaryotic from eucaryotic nitrogen uptake, Picoplankton utilized mainly...
Seasonal and diel changes in nutrient concentrations and nitrogen assimilation rates were used to assess the effects of NH4+ on NO3- assimilation. Surface-water NO3- concentrations ranged from 6 to 17 μM while NH4+ concentrations ranged from 0 to 0.4 μM. Total N assimilation ranged from 84 to 732 nM d–1...
The purpose of this study was to test the hypothesis that NH4+ uptake by heterotrophic bacteria in the subarctic Pacific is C limited. Addition of glucose (0.5–1.0 μM) stimulated NH4+ uptake in unfractionated water but had no effect on bacterial abundance. Glucose stimulation of NH4+ uptake was even greater in...
Oregon State University Libraries has developed a variety of digital collections that support the university‘s commitment to natural resources research. Two of these collections are the Umpqua Basin Explorer and the Middle East Water Collection. The existence of both of these digital initiatives represents the ongoing collaborative work between librarians,...
Although the Dunns’ learning styles and Gardner’s multiple intelligences theories are two distinct areas of research, they do not oppose each other and can be used together to improve learning. The design of this tutorial is an attempt to integrate students’ learning styles and their unique blend of intelligences in...
The concentration of dissolved molybdenum has been determined in several profiles from the Northeast Pacific Ocean. The salinity-normalized concentration is essentially constant in all open-ocean samples (107 nM, lσ = 2.5 nM). The dissolved distribution is not significantly affected by biological cycling.
Flux estimates show that upward mixing of the deep-water nitrate pool accounts for more than 85% of the total new nitrogen input to the euphotic zone of Crater Lake. Because measured primary productivity (360 mg C m-2 d-1) is 10–30 times higher than a level supported solely by the input...
We present observations of the evolution of a deep-mixing event in a deep, temperate lake. The observations were obtained from thermistors mounted on a long-term mooring in the lake. The event seems to have originated near 150-m depth and resulted in a plume or layer of cold water from the...
This study assesses the role of the atmospheric dry fallout as a source of new nitrogen and phosphorus to the surface Levantine seawater. Leaching experiments of inorganic nitrogen (LINO-3, LINH+4) and phosphorus (LIPO4), using SE Mediterranean surface seawater, were performed on 41 aerosol (hereafter dust) samples collected on Whatman 41...
A pair of hydrographic sections, one north and one south of Cape Blanco at 42.9N, was sampled in five summers (1998–2000 and 2002–2003). The NH line at 44.6N lies about 130 km south of the Columbia River, and spans a relatively wide shelf off Newport, Oregon. The CR line at...
Until recently, studies of the fate of primary production in coastal upwelling systems have focused mainly on export through sinking of particulate organic matter (POM). In week-long deck incubations conducted during the upwelling season off Oregon, a large accumulation of carbonrich (C:N ≥ 16) dissolved organic matter (DOM) occurred following...
Despite the importance of the spring phytoplankton bloom off Oregon as a food source for zooplankton, little is known about the sources of phytoplankton seed stock for the bloom or its timing. Experiments were conducted in the late winter to determine if the benthic boundary layer (BBL) could be a...
The stable isotope 15N was used to measure nitrogen uptake in the coastal upwelling region off Oregon and Washington, USA, where nitrate concentrations in the surface water ranged from 0.7 to 49.1 μM. Nanoplankton biomass (1 to 10 pm) was relatively more abundant at low-nitrate stations, while netplankton biomass (10...
The relationship between nitrogen (N) availability and the growth of macroalgae in a seasonal upwelling region (Yaquina Head, Oregon, USA) was investigated. Water column nutrient concentrations were relatively high and stable during the winter, decreased in early spring, and were highly variable in the summer and early fall. Periods of...
Ammonium uptake and regeneration rates were measured in time course experiments with 15N as a tracer. Both ammonium uptake and regeneration rates measured over 12 to 18 h remained essentially constant. However, as the length of the incubations increased the amount of usable data decreased dramatically due to substrate depletion...
An aging electricity distribution system and reduced availability of naturally durable tropical hardwoods in Australia will
combine in the next decade to produce a major shortage of poles. One approach to mitigating this shortage is to utilize lower
durability species and improve the penetration of preservatives into the refractory heartwood...
The seasonal variation in the alongshore velocity field is inferred from direct current observations made over the Oregon continental shelf at various locations and irregular intervals since 1965. Monthly mean currents are computed and compared with earlier studies to give a description of the seasonal variation in the alongshore currents....
The objective of this study was to compare two techniques for estimating benthic fluxes of nutrients (nitrate, phosphate, and silicic acid) and Ge/Si flux ratios. In situ flux chambers were deployed, and cores were collected and incubated at 9 sites along the California margin in July 2001. Both techniques were...
Small temporal and spatial variations in the distribution of dissolved oxygen in Crater Lake, Oregon, are used to estimate the mean age of the lake’s deep water, the flux of labile organic carbon to the deep lake, and the influence of hydrothermal activity on the concentration of dissolved oxygen within...
Active inputs of thermally and chemically enriched fluids at the bottom of Crater Lake create small vertical and horizontal heterogeneities in the deep-lake temperature and salt distribution. Using an internally recording CTD and a precise definition for salinity as a function of in situ conductivity and temperature, we assess the...
On average, the water column of Lake Superior is undersaturated with respect to dissolved oxygen and supersaturated with respect to carbon dioxide during the summer-stratified period. On the basis of temporal changes in water column dissolved oxygen, we calculate rates of oxygen consumption that range from 0.19 to 0.75 mmol...
We measured oxygen consumption rates, the activities of citrate synthase (CS) and lactate dehydrogenase (LDH) and protein contents for over 30 species of deep-sea pelagic Copepoda. The lowest oxygen consumption rates were measured in Euaugaptilus magnus and the highest rates were measured in Paraeuchaeta tonsa. Weight-specific oxygen consumption rates declined...
A total of 19 species of hyperiid amphipods was collected from 1963 to 1967 off Oregon.
Parathemisto pacifica, Paraphronima gracilis, Streetsia challengeri, Tryphana malmi, Hyperia
medusarum, Hyperoche medusarum, and Primno macropa were common. New distributional
records are reported for Scina crassicornis bermudensis and Lanceola loveni. Abundance and
occurrence of common...
Much of our present knowledge about the species composition and distribution of (ephalopods of the Pacific Ocean is derived from collections made on cruises of the "Albatross," steamer of the U.S. Fish Commission, During the late nineteenth and early twentieth centuries. "Albatross" collections along the west coast of North America...
Rates of sediment community oxygen consumption determined in situ are compared to fluxes predicted from oxygen microelectrode gradients measured in cores from ~3,750-m water depth in the eastern North Pacific. Oxygen concentrations decrease exponentially over > 1.5 cm and suggest that organic matter in the sediments is degraded most rapidly...
A temporal record of oxygen and NO3- concentrations in the bottom water of the Santa Barbara Basin indicates that outside waters spill over into the basin seasonally. It is proposed that an annual bottom-water cycle leads ultimately to varve production.
As evidence in support of a benthic mechanism for varve...
We made stable and rapid-responding pH and pCO2 microelectrodes. The pH microelectrode has a ~100-μm-diameter half-sphere bulb tip of pH glass, and the pCO2 sensor has a 200–300-μm-diameter silicone-membrane covered tip. Because the pH microelectrodes have electrical resistances that arc > 1O[to the tenth] ohms, all electrical connections are kept...
We have developed and successfully collected data with a unique, bottom-transecting vehicle (ROVER) that permits the first long time-series measurements of sediment community oxygen consumption (SCOC). This instrument has the, following capabilities: (1) it operates as an autonomous, free vehicle on the sea floor to 6,000-m depth for periods up...
Submillimeter depth distributions of total dissolved inorganic carbon (DIC) were derived from pH and PCO2 profiles measured with microelectrodes in an organic-rich, laboratory-maintained sediment. The DTC profiles were used to calculate diffusive fluxes of DIC across the sediment-water interface. In two experiments, the calculated diffusive fluxes fell within ±50% of...
Three general types of swimbladders were found in the eight species of myctophids studied: gas-filled, fat-invested, and atrophied or reduced. Small specimens of all species had thin-walled, gas-filled swimbladders. Large specimens of Stenobrachius leucopsarus had fat-invested swim-bladders and large Diaphus theta had either gas-filled or atrophied swimbladders, as found by...
A new midwater trawl for sampling deepsea nekton from discrete
depths is described. Its mouth area is about 50 m2. The trawl body is
lined with small mesh netting and terminates in a 5-net opening-closing
codend device. Problems of delayed flushing of animals into the codend
and of entanglement of...
Infrared radiometers, photographs, and a multispectral
scanner were used in a remote sensing study of the ocean off
Oregon during the summer of 1969. Upwelling appeared on
infrared temperature maps as a zone of cold water along the
coast and Columbia River water appeared as a warm water
"plume". Sharp...
In this study we present new information on seasonal variation in absolute growth rate in length of coho salmon (Oncorhynchus kisutch) in the ocean off Oregon and Washington, and relate these changes in growth rate to concurrent changes in the spacing of scale circuli. Average spacing of scale circuli and...
Research on the ecology of salmon in the northeast Pacific Ocean began in the early 20th century. Charles Gilbert and Willis Rich demonstrated the basis for the stock concept and were instrumental in changing common misconceptions of the times. Later in the 1900s, research endeavors, primarily under the auspices of...
Sixteen species of oceanic shrimps, seven Penaeidea and nine Caridea, appeared in 244 collections made within the upper 1500 m at one station in the northeast Pacific off Oregon. Most of the species were primarily mesopelagic in distribution. The most abundant species, Sergestes similis, was the only shrimp common in...
Increasing international trade and tourism have led to an increase in the introduction of exotic pests that pose a considerable economic threat to the agro-ecosystems of importing countries. Scale insects (Sternorryncha: Coccoidea) may be contaminants of export consignments from the South African deciduous fruit industry to the European Union, Israel,...
A closed-tube bioassay with Poria placenta was used to measure residual fungistatic vapors in wood fumigated with methylisothiocyanate (MIT). This bioassay showed an inverse linear relationship between fungal growth and the amount of MIT in the wood samples. For fumigated increment-core sections of unseasoned Douglas-fir heartwood (4.8 mm in diameter...
High-resolution records of δ¹⁸0 and relative abundances of planktonic foraminifers were generated for ODP Leg 138 Site 846 for the past 800 k.y., with an average sampling interval of 3.6 k.y. The time scale was constructed by correlating the benthic δ¹⁸0 record to the SPECMAP and ODP Site 677 δ¹⁸0...
Tanoak (Lithocarpus densiflorus (Hook. and Arn.) Rehder) is highly susceptible to sudden oak death, a disease caused by the oomycete Phytophthora ramorum Werres, De Cock & Man in’t Veld. Symptoms include a dying crown, bleeding cankers, and, eventually, death of infected trees. The cause of mortality is not well understood,...
During Leg 138, we measured reflectance spectra in the visible and near-infrared bands (455-945 nm) every few centimeters on split core surfaces from eastern tropical Pacific Ocean sediments. Here, we evaluate predictions of the content of biogenic calcite, biogenic opal, and nonbiogenic sediments from the reflectance spectra. For Sites 844...
Establishing true depths of recovered sediments is critical to determining sedimentation rates for high-resolution paleoclimatic
studies. We have corrected the composite depth scale, which accounts for the entire continuous sedimentary sequence, so that sediment
depths are consistent with logging depths, or "true" depths. We accomplished this by taking advantage of...
High resolution, continuous records of GRAPE wet bulk density (a carbonate proxy) from Ocean Drilling Program Leg 138
provide one the opportunity for a detailed study of eastern equatorial Pacific Ocean carbonate sedimentation during the last 6 m.y.
The transect of sites drilled spans both latitude and longitude in the...
A stable-isotope stratigraphy at Site 846 (tropical Pacific, 3°06'S, 90°49'W, 3307 m water depth), based on the benthic
foraminifers Cibicides wuellerstorfi and Uvigerina peregrina, yields a high-resolution record of deep-sea δ¹⁸O and δ¹³C over the
past 1.8 Ma, with an average sampling interval of 3 k.y. Variance in the δ¹⁸O...
The primary objective of Leg 138 was to provide detailed information about the ocean's response to global climate change
during the Neogene. Two north south transects were drilled (95° and 110°W) within the region of equatorial divergence driven
upwelling (and thus high accumulation rates and resolution) and spanning the major...
Calcium carbonate percentages at five Ceara Rise sites were estimated at 1- to 2-k.y. intervals over the past 5 m.y., using
reflectance spectroscopy and magnetic susceptibility proxies. From these estimates and detailed correlations between sites, gradients
of calcite and terrigenous sediment accumulation rates in a depth transect of sites reveal...
Pollen analyses of sediments from Holes 1019C, 1019E, 1020C, and 1020D as well as piston Core EW9504-17 provide
continuous, chronostratigraphically controlled proxy vegetation and climate data for coastal northwest North America for the
last ~500 k.y. Systematic changes in the representation of the diagnostic components of northern California plant assemblages...
We analyzed the unsaturation ratio (U k/37 ) of long-chain ketones—a molecular sea-surface temperature (SST) indicator—concentrations of carbonate and organic carbon in sediments from Site 846 in the eastern equatorial Pacific Ocean. Based on an isotopic age model for the composite depth section of 0-46 m below seafloor and on...
During ODP Leg 138, we tested a prototype instrument, developed
at Oregon State University, for measuring light reflectance in 511
channels of the visible and near-infrared bands. The technique of
reflectance spectroscopy has been used for some time in chemistry
and mineralogy (e.g., Hunt, 1977; Gaffey, 1986) and has found...
To facilitate the selection of drill sites for Leg 138, a site survey
program was conducted on board the Scripps Institution of
Oceanography's research vessel Thomas Washington (Cruise Venture
1). During this cruise, which departed San Diego on 30 August 1989
and arrived in Manzanillo, Mexico, on 4 October 1989,...
Sediments from five Leg 167 drill sites and three piston cores were analyzed for C[subscript ORG] and CaCO₃. Oxygen isotope stratigraphy on benthic foraminifers was used to assign age models to these sedimentary records. We find that the northern and central California margin is characterized by k.y.-scale events that can...
The chemical composition of the boles of 14 Douglas-fir trees growing in the central Willamette Valley of western Oregon was examined to determine whether differences in various chemical component levels might help to explain arthropod or microbial colonization patterns. Levels of nearly all cations as well as N and P...
The effect of various wood characteristics on decomposition of metham sodium to methylisothiocyanate in sixteen North American and Southeast Asian hardwoods and softwoods was investigated. While marked differences were noted in the degree of decomposition among some species, the relationship between decomposition and lignin content, extractive levels, wood pH, or...
Wood that is submerged in fresh water for long periods has increased permeability and other changed properties. Wood that is submerged in salt water may absorb considerable quantities of salts, which may render the wood resistant to microbial colonization. In this report, we describe decay tests on Douglas-fir sapwood and...
Basamid (3,5-dimethyl-l,3,5,2H-tetrahydrothiadiazine-2-thione), a crystalline powder first used as a soil sterilant, has shown promise as a wood fumigant. This chemical decomposes to methylisothiocyanate (MITC), the primary active ingredient, as well as other products; but the rate of decomposition in wood is too slow to be effective unless certain catalysts are...
The levels of copper, chromium, and arsenic in soil surrounding CCA-treated posts and beneath CCA-treated stakes were investigated at a plot near Gainesville, Florida. Metal levels were elevated in soil immediately adjacent to the treated wood, but decreased with distance away or depth. Mean extractable arsenic levels ranged from 1.74...
A small block test was used in assessing whether pelletized sodium n-methyldithiocarbamate (NaMDC) would decompose and produce methylisothiocyanate (MITC) and thereby eliminate Antrodia carbonica colonies from Douglas-fir heartwood. Also evaluated were the effects of wood moisture content, dosage, incubation period, pH level, and presence of copper sulfate on percentage of...
The bioassay with Aspergillus niger is a simple way of determining the presence and amount of pentachlorophenol or tributyltin oxide in wood, but it does not appear useful for measuring strongly fixed chemicals such as chromated copper arsenate, borate, and fluoride. Its effectiveness in detecting other preservatives has not been...
Impact bending and breaking radius were used to measure loss in toughness caused by basidiomycetes isolated from wood. Small test pieces were used to accelerate testing. Wide differences were found among, and sometimes within, the 26 species tested. Brown-rot fungi tended to cause greater losses than white-rot fungi, but no...
Hyphal fragments and protoplasts of two wood-degrading fungi, Postia placenta and Trametes versicolor, were used to examine the effects of two fungicides, copper sulfate and azaconazole, on fungal health (as measured by oxygen consumption, glucose utilization, potassium levels, cell regeneration, and copper uptake). Although both cell systems responded to the...
The ability of 15 bacterial and fungal isolates to inhibit fungal stain of ponderosa pine sapwood was studied on small wood samples exposed in a moist environment. Several isolates including Bacillus subtilis were capable of inhibiting fungal stain although the protective effect was lost upon prolonged exposure. More detailed evaluations...
The influence of moisture content (MC) and conventional preservative treatment on methylisothiocyanate (MIT) sorption and diffusion were investigated in Douglas-fir wood. In wood at 0% MC, the ratio of equilibrium MIT adsorption to desorption concentrations was low (0.2), but it increased rapidly to about 0.94 above 18% MC. Partition coefficients...
The heartwood of western redcedar (Thuja plicuta) is known for its natural resistance to fungal attack, but some users of western redcedar utility poles have suggested that its durability may be diminished as suppliers begin to harvest trees from younger stands. The decay resistance of western redcedar samples from the...
This study evaluated the effects of pretreatment incising of dry lumber and preservative treatment on the shear strength of 1980 pieces of 2 X 4 dimension lumber (nominal 50 mm X 100 mm X 3.6 m long). Three species groups (Douglas-fir, Hem-Fir. and Spruce-Pine-Fir-South) and two commercially produced machine-stress-rated grades...